The museum said inductees are judged on whether they are widely respected and remembered and must be more than a “passing fad.” Other considerations include how the toys foster creativity and learning, and whether they profoundly change play for children.

Fisher-Price Little People hit the market in 1959. The first sets, made of wood, included a circular head and a simple cylindrical body. The toys were then revamped in 1991 after complaints they were a choking hazard. The new versions were wider and designers later added arms, legs and more detailed faces.

The fantasy board game Dungeons & Dragons first appeared in 1974, and its popularity quickly grew beyond school-aged children.

“More than any other game, Dungeons & Dragons paved the way for older children and adults to experience imaginative play,” curator Nic Ricketts said in a statement.

Ricketts said the game is especially significant because its mechanics were adaptable to computer games, which, in party, led to the success of online roleplaying games like World of Warcraft.

The swing, a staple on playgrounds and in many children’s backyards, is the oldest of the three inductees. Depictions of the swing can be found on Greek vases dating back to about 500 B.C.

“Though the equipment has evolved with the centuries, the pleasure children and adults find in swinging has hardly changed at all,” curator Patricia Hogan said in a statement.

The new inductees will join 59 other classic toys at The Strong National Museum of Play.

In 1998, the museum inducted the first toys into its hall of fame, including Barbie, the teddy bear, Play-Doh, Erector Set, Etch A Sketch, Monopoly, marbles, Crayola crayons, LEGO, and Frisbee.